Directly make the background of the QR code image transparent (Recommended learning: PHP video tutorial)
//二维码内容
$qrcodeContent = '此处存链接的话，参数不宜过长，否则导致生成二维码时间太长！！！';
//容错级别
$errorCorrectionLevel = 'L';
//生成图片大小
$matrixPointSize = 6;
//生成二维码图片
\QRcode::png($qrcodeContent, 'qrcode.png', $errorCorrectionLevel, $matrixPointSize, 2);
$QR = 'qrcode.png';//已经生成的原始二维码图
//将二维码背景变透明
$resource = imagecreatefrompng($QR);
@unlink($QR);
$bgcolor = imagecolorallocate($resource, 255, 255, 255);
imagefill($resource, 0, 0, $bgcolor);
imagecolortransparent($resource, $bgcolor);
imagepng($resource,'qrcode_copy.png'); /*先处理成透明图再进行缩放就不会出现白黑点情况了！！！（至少效果好多了，而先进行缩放再处理背景透明就会出现很多白黑点！）*/
@imagedestroy($resource);
//获取对应游戏海报二维码位置
$qrcode_pos = $pos;//$pos = [x,y]
//获取对应游戏海报二维码规格
$qrcode_spec = $spec;//$spec = [w,h]
$resource = smart_resize_image('qrcode_copy.png', $qrcode_spec[0], $qrcode_spec[1], true);
imagepng($resource,'qrcode_'.$gameType.'.png');//存储改变大小后的透明二维码
$qrcode = 'qrcode_'.$gameType.'.png';
//将透明背景的二维码贴到海报图指定位置
$poster_with_qrcode_or_invitedcode_url = waterImage($posterUrl, $qrcode, $qrcode_pos[0], $qrcode_pos[1]);
@imagedestroy($resource);
@unlink('qrcode_copy.png');
@unlink($qrcode);The above calling method is as follows:
/**
* 调整图片大小并返回图片资源
* @param $file
* @param int $width
* @param int $height
* @param bool $proportional
* @return bool|resource
* @author zsb
*/
function smart_resize_image($file, $width = 0, $height = 0, $proportional = false)
{
if ( $height <= 0 && $width <= 0 ) {
return false;
}
$info = getimagesize($file);
$image = '';
$final_width = 0;
$final_height = 0;
list($width_old, $height_old) = $info;
if ($proportional) {
if ($width == 0) {
$factor = $height/$height_old;
}elseif ($height == 0) {
$factor = $width/$width_old;
}else {
$factor = min ( $width / $width_old, $height / $height_old);
}
$final_width = round ($width_old * $factor);
$final_height = round ($height_old * $factor);
}else {
$final_width = ( $width <= 0 ) ? $width_old : $width;
$final_height = ( $height <= 0 ) ? $height_old : $height;
}
switch ($info[2]) {
case IMAGETYPE_GIF:
$image = imagecreatefromgif($file);
break;
case IMAGETYPE_JPEG:
$image = imagecreatefromjpeg($file);
break;
case IMAGETYPE_PNG:
$image = imagecreatefrompng($file);
break;
default:
return false;
}
$image_resized = imagecreatetruecolor( $final_width, $final_height );
if ( ($info[2] == IMAGETYPE_GIF) || ($info[2] == IMAGETYPE_PNG) ) {
$trnprt_indx = imagecolortransparent($image);
// If we have a specific transparent color
if ($trnprt_indx >= 0) {
// Get the original image's transparent color's RGB values
$trnprt_color = imagecolorsforindex($image, $trnprt_indx);
// Allocate the same color in the new image resource
$trnprt_indx = imagecolorallocate($image_resized, $trnprt_color['red'], $trnprt_color['green'], $trnprt_color['blue']);
// Completely fill the background of the new image with allocated color.
imagefill($image_resized, 0, 0, $trnprt_indx);
// Set the background color for new image to transparent
imagecolortransparent($image_resized, $trnprt_indx);
}
// Always make a transparent background color for PNGs that don't have one allocated already
elseif ($info[2] == IMAGETYPE_PNG) {
// Turn off transparency blending (temporarily)
imagealphablending($image_resized, false);
// Create a new transparent color for image
$color = imagecolorallocatealpha($image_resized, 0, 0, 0, 127);
// Completely fill the background of the new image with allocated color.
imagefill($image_resized, 0, 0, $color);
// Restore transparency blending
imagesavealpha($image_resized, true);
}
}
imagecopyresampled($image_resized, $image, 0, 0, 0, 0, $final_width, $final_height, $width_old, $height_old);
return $image_resized;
}
/**
* 获取图片信息
* @param $filename 传过来的参数是文件名字符串
* @return mixed 返回值是一个数组，包含图片宽度、高度、创建和输出的字符串以及扩展名
* @author zsb
*/
function getImageInfo($filename){
if(@!$info = getimagesize($filename)){//getimagesize()函数可以得到文件信息,
//还可以判断图片是否为真实的图片类型，详细功能见PHP手册
exit('文件不是真实图片');
}
$fileInfo['width'] = $info[0];
$fileInfo['height'] = $info[1];
$mime = image_type_to_mime_type($info[2]);//info[2]这个是图片类型对应的数字，此函数可以根据该数字返回出文件对应的MIME类型，详细见手册
$createFun = str_replace('/', 'createfrom', $mime);//将$mime中的'/'替换成'createfrom'，
//因为后边要用到imagecreatefromjpeg/jpg/png 这个函数，这样就可以动态使用不同的函数了
$outFun = str_replace('/', '', $mime);
$fileInfo['createFun'] = $createFun;
$fileInfo['outFun'] = $outFun;
$fileInfo['ext'] = strtolower(image_type_to_extension($info[2]));//image_type_to_extension()是得到文件后缀名函数
return $fileInfo;//返回文件信息
}
/**
* 给图片加水印并返回新图片地址
* @param $dstName
* @param $srcName
* @param int $x 图片水印的位置 (0,0)代表左上角
* @param int $y 图片水印的位置 (0,0)代表左上角
* @param string $dest 默认保存的位置
* @param string $pre 默认文件名前缀
* @param int $pct 图片水印的透明度
* @return string
* @author zsb
*/
function waterImage($dstName, $srcName, $x = 0, $y = 0, $dest = 'images/waterImage', $pre = 'waterImage_', $pct = 100){
//获取图片信息
$dstInfo = getImageInfo($dstName);
$srcInfo = getImageInfo($srcName);
//创建画布
$dst_im = $dstInfo['createFun']($dstName);
$src_im = $srcInfo['createFun']($srcName);
$src_width = $srcInfo['width'];
$src_height = $srcInfo['height'];
$dst_width = $dstInfo['width'];
$dst_height = $dstInfo['height'];
imagecopymerge($dst_im, $src_im, $x, $y, 0, 0, $src_width, $src_height, $pct);
if($dest && !file_exists($dest)){
mkdir($dest,0777,true);
}
//$randNum = mt_rand(100000,999999);
$dstName = "$pre".$dstInfo['ext'];
$destination = $dest ? $dest.'/'.$dstName : $dstName;
$dstInfo['outFun']($dst_im,$destination);
imagedestroy($src_im);
imagedestroy($dst_im);
return $destination;
}The above is the detailed content of How to make QR code transparent in php. For more information, please follow other related articles on the PHP Chinese website!
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